Question 1191337

let  nickels be {{{n}}} and quarters {{{q}}}

if he now has {{{16}}} nickels and quarters, then we have

{{{n+q=16}}}

{{{n=16-q}}}

since
{{{1n=5c }}}
{{{1q=25c}}}

total amont of cents will be {{{5(16-q)+25q}}}


If Bob had twice as many nickels and half as many quarters, 

{{{2(5n)+(25q)/2}}} he would have {{{60c}}} less 


{{{2(5(16-q))+(25q)/2=5(16-q)+25q-60}}}

{{{q = 8}}}

=>{{{n=8}}}

check: total amount of cents

{{{5(16-8)+25*8=240c}}}

If Bob had twice as many nickels and half as many quarters,

{{{2*5(16-8)+(25*8)/2=180c}}}

difference:{{{240c-180c=60c}}}